Selective Receipt in Certified E-mail

Traditional pen and paper transactions are becoming more and more replaced by equivalent electronic services. Therefore electronic e-mail should also provide enhanced services as those provided by traditional mail. In this paper we present new optimistic protocols for certified e-mail. The major contribution of our paper is the definition of a new property, specific to certified e-mail: no author-based selective receipt. This property requires that once the identity of the author of the mail is known, the receipt can not be refused any more. We present two certified e-mail protocols respecting this property.